KR101381056B1 - Growth method of iii-nitride-based epi on si substrates and the semiconductor substrates - Google Patents

Abstract

A semiconductor substrate on which the III-nitride epitaxial layer of the present invention is grown includes a substrate; A transfer layer formed on the substrate and melted by a predetermined high temperature; A buffer layer formed on the transfer layer; And a III-nitride epitaxial layer formed of a Group III nitride material on the buffer layer.
According to the present invention, it is possible to solve the stress due to lattice constant mismatch and thermal expansion coefficient mismatch between the III-nitride epitaxial layer and the semiconductor substrate by forming a transfer layer between the III-nitride epitaxial layer and the semiconductor substrate. It is possible to provide a semiconductor substrate having grown III-nitride-based epi layer and a method thereof.

Description

Growth Method of III-Nitride-based Epi on Si Substrates and the Semiconductor Substrates

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate on which a III-nitride epitaxial layer is grown, and a method thereof, and more particularly, to forming a transfer layer between a III-nitride epitaxial layer and a semiconductor substrate to utilize a melting characteristic to form a III-nitride epitaxial layer. The present invention relates to a semiconductor substrate and a method of growing a III-nitride-based epi layer capable of resolving stress caused by lattice constant mismatch and thermal expansion mismatch.

Recently, there is a great need to cope with the method of increasing the limits of high-speed operation and withstand voltage characteristics provided by silicon semiconductors in power semiconductor devices. Despite the ease of product development for FET devices in recent years, the performance of devices in terms of operating speed, power consumption, over-voltage, reliability, and power driving still needs to be improved.

Thus, attention has been paid to high power high voltage devices using III-Nitride-based semiconductors such as GaN having high heat resistance and high withstand voltage characteristics. However, the role of silicon-based power semiconductors is still required in terms of device long-term reliability. That is, the silicon-based advantage can be utilized to solve electrostatic and thermal-electrical instability in GaN-based FETs having high speed and high voltage characteristics.

As described above, the GaN-based device is mounted on a silicon substrate and integrated with the silicon device, thereby achieving enormous performance, productivity, and reliability. However, this requires the formation of an excellent crystalline III-Nitride epilayer on the silicon substrate.

The substrates used in the prior art are Si, sapphire, ZnO, and SiC in most cases, and there are no cases or patents using a heavily doped SiGe-based epilayer as an interlayer. Therefore, most of the cases still contain problems of GaN-based III-Nitride-based semiconductor devices, reliability is a problem, and development of new device structures and fabrication techniques that improve thermal and electrical performance is an important technical issue.

In addition to these thick insulating sapphire and silicon carbide substrates, transparent conductive zinc oxide (ZnO) has a small lattice constant with nitride-based semiconductors, good electrical and thermal conductivities, and excellent light transmittance. ), And because of the low cost (Cheap) has been spotlighted as the substrate of the next-generation nitride-based light emitting device. However, this ZnO-based Oxides system is decisively easy to decompose due to surface instability at high temperatures of 600 degrees Celsius and high vacuum of 10 −3 power Torr, and also hydrogen (H 2) or ammonia It is almost impossible to grow a single crystal nitride semiconductor in a high temperature and a reducing atmosphere of more than 800 degrees by more actively reducing in a reducing atmosphere such as).

Still other popular conductive substrates are silicon (Si), silicon low manganese (SiGe), and gallium arsenide (GaAs) materials. They also cause material deformation / decomposition due to the motion of dislocation slip system present inside these substrates at high temperatures of 500 degrees or higher, and large lattice constants and thermal expansion coefficients with nitride semiconductors. Due to thermal expansion coefficients, it is also not easy to grow a high quality nitride based thin film.

Accordingly, devices based on nitride systems are excellent in high speed operation, high voltage operation, and high power operation, but have many crystal defects and are difficult to manufacture in large areas.

Prior art (H. Ishikawa, K. Shimanaka, M. Azfar bin M. Amir, Y. Hara, M. Nakanishi, “Inproved MOCVD Growth of GaN on Si-on-porous-Silicon Substrates,” Phys. Status Solidi C, No. 7-8, pp. 2049-2051 (2010)), when GaN is grown on porous silicon, the separation is serious, so that a lot of holes are seriously formed and low quality GaN thin film is formed. Therefore, by growing and using the Si-epi layer on the porous Si, it is possible to grow a GaN epi layer having excellent mirror crystallinity with very few cracks. In addition, no new voids are formed between AlN and porous silicon. However, a technical problem remains that it is difficult to completely remove the voids and microscopic pin holes on the surface of the original porous silicon.

1 is a view showing the generation of cracks according to the growth of the III-Nitride-based epilayer on a silicon substrate according to the prior art. As shown in FIG. 1, the lattice mismatch applied to the III-Nitride-based epilayer in the (III-Nitride) -on-Si structure is -17% and the thermal expansion coefficient (TEC) is 57%. . Therefore, during epitaxial growth, the GaN epitaxial layer has many crystal defects including dislocations such as 10 ⁸ to 10 ¹⁰ cm ^-2 , and tensile stress is induced to deform the wafer into a concave shape. In addition, cracks are generated due to the difference in TEC in the process of lowering the temperature to room temperature after the epitaxial growth is completed.

This physically deformed III-Nitride-based epilayer is a key problem that provides a decisively impossible cause for fabricating a precise semiconductor device thereon. In addition, the III-Nitride-based epi layer and the silicon substrate are suddenly destroyed even with a slight external physical impact.

Therefore, a technique capable of accommodating the physical strain of relaxation such as relaxation caused by lattice mismatch applied between the silicon substrate and the III-Nitride-based epi layer and strain ~ 57% due to a mismatch between ~ 17% and thermal expansion coefficient need. To make up for this weakness, 1 ~ 3mm thick silicon substrates are specially manufactured and used, which is difficult to use the semiconductor process equipment, and it is not desirable because of the difficulty of using semiconductor processing equipment.

The technical problem to be solved by the present invention is to form a transfer layer between the III-nitride epitaxial layer and the semiconductor substrate to utilize the melting characteristics by the lattice constant mismatch and thermal expansion coefficient mismatch of the III-nitride epitaxial layer and the semiconductor substrate The present invention provides a semiconductor substrate and a method of growing a III-nitride-based epi layer capable of resolving stress.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise forms disclosed. It will be possible.

A semiconductor substrate on which the III-nitride epitaxial layer of the present invention for growing the above technical problem is grown, the substrate; A transfer layer formed on the substrate and melted by a predetermined high temperature; A buffer layer formed on the transfer layer; And a III-nitride epitaxial layer formed of a Group III nitride material on the buffer layer.

Here, in particular, the transfer layer is characterized by being composed of Si _x Ge _{1 - x} .

In particular, the transfer layer is characterized in that the growth of the epi layer is changed by changing the Si _x Ge _{1 -x} composition ratio according to the type of the substrate or the nitride based epi layer.

Here, in particular, the transfer layer is characterized in that it is formed as a composite layer of a sandwich structure in a single or a plurality of layers depending on the material and composition.

In particular, the substrate is characterized in that it uses a silicon substrate or a sapphire substrate.

In addition, the III-nitride epitaxial growth method of a semiconductor substrate according to the present invention comprises the steps of: forming a transfer layer on the substrate; Forming a buffer layer on the transfer layer; And growing a III-nitride epitaxial layer on the buffer layer while applying a high temperature to melt the transfer layer.

Here, in particular, the transfer layer is characterized by being composed of Si _x Ge _{1 - x} .

In particular, the transfer layer is characterized in that the growth of the epi layer is changed by changing the Si _x Ge _{1 -x} composition ratio according to the type of the substrate or the nitride based epi layer.

Here, in particular, the transfer layer is characterized in that it is formed as a composite layer of a sandwich structure in a single or a plurality of layers depending on the material and composition.

In particular, the transfer layer is characterized by being formed of a semiconductor material having a lower melting point than the buffer layer and the epi layer.

In particular, the substrate is characterized in that it uses a silicon substrate or a sapphire substrate.

In particular, the III-nitride epitaxial layer is characterized in that GaN, InN, AlN and their three-phase, quaternary compound layers are formed of a single or multiple epilayers as a sandwich-like composite layer. have.

In particular, it is characterized in that it further comprises the step of lifting off the buffer layer and the III-nitride epi layer from the transfer layer after the growth of the III-nitride epi layer.

In particular, the lift-off may include applying the high temperature in the chamber after completion of growth of the III-nitride epitaxial layer to melt the transfer layer to lift off the buffer layer and the III-nitride epitaxial layer. It has its features.

In particular, the lifting-off may be performed by etching the transfer layer after completion of growth of the III-nitride epitaxial layer to lift off the buffer layer and the III-nitride epitaxial layer.

According to the present invention, a transfer layer is formed between the III-nitride epitaxial layer and the semiconductor substrate to utilize the melting property to solve the stress due to lattice constant mismatch and thermal expansion coefficient mismatch between the III-nitride epitaxial layer and the semiconductor substrate. It is possible to provide a semiconductor substrate and a method of growing a III-nitride-based epi layer.

1 is a view showing the generation of cracks according to the growth of the III-Nitride-based epilayer on a silicon substrate according to the prior art.
2 is a view schematically showing a structure of a semiconductor substrate on which a III-nitride epitaxial layer is grown according to the present invention.
3A to 3F are flowcharts illustrating a method of manufacturing a semiconductor substrate on which a III-nitride epitaxial layer is grown according to a first embodiment of the present invention.
Figure 4a illustrates a lift off method using the melting of the tracer layer according to the present invention.
Figure 4b is a view showing a lift off method using an etching process when the growth of the epi layer according to the present invention.
5 is a diagram showing the growth characteristics of the epi layer according to the substrate of the present invention.
FIG. 6 is a diagram schematically illustrating a structure of a semiconductor substrate on which a III-nitride epitaxial layer is grown according to a second exemplary embodiment of the present invention.
7A to 7F are flowcharts illustrating a method of manufacturing a semiconductor substrate on which a III-nitride epitaxial layer is grown according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the detailed description of known functions and configurations incorporated herein will be omitted when it may unnecessarily obscure the subject matter of the present invention.

The same reference numerals are used for portions having similar functions and functions throughout the drawings.

In addition, in the entire specification, when a part is referred to as being 'connected' to another part, it may be referred to as 'indirectly connected' not only with 'directly connected' . Also, to include an element does not exclude other elements unless specifically stated otherwise, but may also include other elements.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a view schematically illustrating a structure of a semiconductor substrate on which a III-nitride epitaxial layer is grown according to a first embodiment of the present invention. As shown in FIG. 2, the semiconductor substrate in which the Group III nitride epitaxial layer of the present invention is grown includes a substrate 210 and a transfer layer 220 formed on the substrate 210 and melted by a predetermined high temperature. And a buffer layer 230 formed on the transfer layer 220, and a III-nitride epitaxial layer 240 formed of a group III nitride material on the buffer layer 230.

The substrate 210 may be a silicon substrate or a sapphire substrate.

The transfer layer 220 is a single or multiple Si, C, Ge, Sn, and three-phase, quaternary compound layer of a silicon low germanium (SiGe) -based material injecting a high concentration of impurities on the substrate The epi layer of is formed into a sandwich-like composite layer.

More specifically, the transfer layer 220 is composed of Si _x Ge _{1 - x} , and the growth of the epi layer is changed by changing the Si _x Ge _{1 -x} composition ratio according to the type of the substrate or the nitride based epi layer. can do. In addition, the transfer layer 220 may be formed of a semiconductor material having a lower melting point than the buffer layer 230 and the nitride epitaxial layer 240.

In addition, the transfer layer 220 may be formed as a sandwich layer composite layer in a single or a plurality of layers depending on the material and composition, and adjusts the composition of Si, C, Ge, Sn between 0-1, and impurity The concentration of 10 ¹⁹ ~ 5 × 10 ²¹ cm ^-3 can be formed by adjusting. Here, the transfer layer is melted when raising the temperature for growth of the nitride-based epi layer 240 serves as a floating layer.

The buffer layer 230 is formed on the transfer layer 220 and grows at a temperature lower than the growth temperature of the transfer layer 220.

After the buffer layer 230 is grown, the nitride-based epitaxial layer 240 is formed of a binary system of GaN, InN, AlN, and a three-phase, quaternary compound layer in which each of them is a single or multiple epitaxial layers. It is formed of a sandwich-like composite layer.

In other words, the nitride epitaxial layer allows the nitride epitaxial layer to be finally grown by the floating layer of the transfer layer to have high quality without defects or cracks without being affected by the lattice constant of the semiconductor substrate.

3A to 3F are flowcharts illustrating a method of manufacturing a semiconductor substrate on which a III-nitride epitaxial layer is grown according to a first embodiment of the present invention.

First, as shown in FIG. 3A, a substrate 210 for growing a III-nitride epitaxial layer is provided. In this case, a silicon substrate or a sapphire substrate may be used as the substrate 210.

Subsequently, as shown in FIG. 3B, a transfer layer 220 is formed on the substrate 210. Si, C, Ge, Sn and their three-phase, quaternary compound layers of Si _1-X Ge _X in which a high concentration of impurities are injected onto the substrate 210. It is formed of a composite layer. Here, the composition of Si, C, Ge, Sn is adjusted between 0-1, and the concentration of impurities is formed by adjusting the 10 ¹⁹ ~ 5 × 10 ²¹ cm ^-3 . In this case, the transfer layer 220 may be formed of a semiconductor material having a lower melting point than the buffer layer 230 and the nitride epitaxial layer 240.

More specifically, the transfer layer 220 is deposited by thermal decomposition on a substrate using RPCVD, using DCS gas, SiH ₄ gas, or GeH ₄ gas as the main source gas, and H ₂ gas as the balance gas. You grow by doing it. At this time, the GeH ₄ gas flow rate is adjusted to change the mixing ratio of Ge to 0 to 100% by varying Si _{1 - X} Ge _X Grow the layer.

And, by adjusting the growth temperature and the flow pressure of the variable Si _{1 - X} Ge _X The thickness of the layer is formed in a predetermined nm to a predetermined µm.

The transfer layer 220 is suitable as an interlayer in GaN epitaxial growth by changing the lattice constant and TEC according to the content of Ge. The SiGe epitaxial layer has a low melting temperature and smooth movement of Ge atoms. When stress is applied, relaxation occurs more easily than Si or GaN-based epilayers. In addition, due to the impurities implanted at a high concentration, the atomic defects are high, and the energy of atomic bonding is low, thereby quickly relieving the stress transferred from the Si and GiN epitaxial layers. Similarly, by using the interlayer of the SiGe-based epilayer, the stress between the Si and GaN-based epilayers is alleviated, thereby reducing the warpage of the wafer and minimizing the occurrence of defects on the GaN side.

As shown in FIG. 3C, a buffer layer 230 is formed on the formed transfer layer 220. Here, the buffer layer 230 must be grown at a lower temperature than the transfer layer 220.

Subsequently, as illustrated in FIG. 3D, the transfer layer 220 melts when the temperature is raised for growth of the epi layer after the growth of the buffer layer 230. melting) process.

As shown in FIG. 3E, the nitride layer Epi layer 240 is grown while the transfer layer 220 is melted. Here, the nitride epitaxial layer 240 is a binary or three-phase (quaternary) compound layer of GaN, InN, AlN, and mixed with each other after the buffer layer 230 is grown, single or multiple epi The layer is formed into a sandwich-like composite layer.

More specifically, the method of growing the nitride based epilayer 240 may include VPE (Vapor Phase Epitaxial growth), LPE (Liquid Phase Epita xial growth), and SPE (Solid Phase Epitaxial growth). have. Here, the VPE is to grow crystals on the substrate through decomposition and reaction by heat while flowing the reaction gas on the substrate, depending on the raw material of the reaction gas, hydride VPE (HVPE), halide VPE (halide VPE), organic Metal organic VPE (MOVPE). The present invention uses the HVPE (hydride VPE) method.

If the silicon substrate on which the nitride-based epitaxial layer 240 is grown is charged into an HVPE reactor, GaCl x gas and NH 3 gas are flowed into the reactor and the temperature of the silicon substrate is maintained at 400 to 600 ° C. Then, GaCl x gas and NH 3 gas react with each other to form a GaN seed layer, and then a GaN nanorod is formed on the substrate by itself.

Thus, the grown nitride epitaxial layer 240 is a defect due to lattice mismatch between the semiconductor substrate 210 and the nitride epitaxial layer 240 by the floated transfer layer 220. In the case of the epilayer, which is relaxed in the floating layer and is finally grown, a high-quality epi layer without defects is grown regardless of the lattice constant difference with the semiconductor substrate.

As shown in FIG. 3F, growth of the nitride based epi layer 240 is completed on the buffer layer 230 through the above process.

4A is a view illustrating a lift-off method using melting of the tracer layer according to the present invention. As shown in FIG. 4, a lift off method using melting of the transfer layer 220 is shown, and growth of the nitride-based epi layer 240 is started. And the transfer layer 220 remains in a melted state until the growth is completed. After the growth of the nitride-based epi layer 240 is completed, the transfer layer 220 is completely melted to remove the temperature in the chamber. The nitrile epitaxial layer 240 can be easily obtained by having the advantage of being naturally lifted off.

Figure 4b is a view showing a lift off method using an etching process when the growth of the epi layer according to the present invention. As shown in FIG. 4B, when the growth of the nitride based epi layer 240 is completed, the nitride based epi layer 240 is lifted off through an etching process. In the etching method, dry or wet etching is performed depending on the selectivity of the semiconductor substrate 210, the transfer layer 220, and the grown nitride layer 240. It is made by using a semiconductor-based recycling through this has an economic advantage.

On the other hand, Figure 5 is a diagram showing the growth characteristics of the epi layer according to the substrate of the present invention. As shown in FIG. 5, substrate-related characteristics of GaN-on-sapphire, GaN-on-Si, GaN-on-SiC, and GaN-on-SiGe are shown. At this time, in the case of GaN-on-sapphire substrate, GaN-based epitaxial growth technology can be easily secured, an insulating substrate can be used, and stable at high temperature. However, it is disadvantageous for vertical devices and has low thermal conductivity, which shows disadvantageous features for power devices.

In the case of GaN-on-Si, the epitaxial process is simple, manufacturing cost is low, and silicon doping and device integration are easy. However, cracks are serious due to lattice mismatch or thermal expansion gap, and are vulnerable to thermal and mechanical shock.

In the case of GaN-on-SiC, GaN-based epitaxial growth technology can be easily secured, an insulating substrate can be used, high thermal conductivity, and stable at high temperature. However, the substrate is expensive, the reliability is low, and the size of the substrate is limited, resulting in low productivity. In the case of GaN-on-SiGe, it is possible to control stress, to control relaxation process, to integrate with silicon semiconductor, to lift-off using wet etching, and to reuse silicon substrate. Here, the crystallinity and electrical properties of the III-Nitride-based epilayer are superior to those of a very simple structure such as GaN-on-Si in which a GaN epilayer is directly grown on a silicon substrate, but the manufacturing cost of the substrate is slightly increased.

FIG. 6 is a diagram schematically illustrating a structure of a semiconductor substrate on which a III-nitride epitaxial layer is grown according to a second exemplary embodiment of the present invention. As shown in FIG. 6, the semiconductor substrate in which the Group III nitride epitaxial layer of the present invention is grown includes a substrate 610 and a multilayer transfer layer formed on the substrate 610 and melted by a predetermined high temperature. 620, a buffer layer 630 formed on the transfer layer 620, and a III-nitride epitaxial layer 640 formed of a group III nitride material on the buffer layer 630.

That is, the nitride layer epi layer 640 is grown using a transfer layer 620 having a multi-layer structure. In this case, when the transfer layer 620 is formed of a single material as well as a layer according to a material or composition of binary or ternary materials, the transfer layer 620 may be used through various methods. There is an advantage that can be adjusted to the conditions suitable for the melting temperature and lift off (lift off) of the nitride-based epi layer (Epi layer) (620).

7A to 7F are flowcharts illustrating a method of manufacturing a semiconductor substrate on which a III-nitride epitaxial layer is grown according to a second embodiment of the present invention.

First, as shown in FIG. 7A, a substrate for growing a group III nitride epitaxial layer is provided. In this case, a silicon substrate or a sapphire substrate may be used as the substrate 610.

More specifically, a second step is performed on a silicon (Si) substrate by floating epitaxy, which grows by utilizing a structure in which a Ge epilayer is placed between the group III nitride epitaxial layer and the silicon (Si) substrate as a transfer layer. The epitaxial layer of Ge is minimized by using a growth method and a buffer layer. Subsequently, the group III nitride buffer layer is formed at a low temperature. Subsequently, when the chamber temperature is increased for high temperature growth, the Ge layer, which is a transfer layer, is melted, and a floating epitaxy mechanism is applied thereto, whereby the grown III-Nitride epilayer is formed by lattice constant of Si substrate. Regardless, it grows into a high quality thin film without defects.

In addition, a Ge epi layer is formed between the Group III nitride epitaxial layer and the sapphire substrate to apply a floating epitaxy mechanism.

Subsequently, as shown in FIG. 7B, a transfer layer 620 is formed on the substrate 610. Si, C, Ge, Sn and their three-phase, quaternary compound layers of Si _1-X Ge _X in which high concentrations of impurities are injected onto the substrate 610 are sandwiched by single or multiple epi layers. It is formed of a composite layer. Here, when the transfer layer 620 is composed of a single material as well as a sandwich layer according to a binary or ternary material and composition, the melting temperature of the semiconductor substrate and the grown epi layer and There is an advantage that can be adjusted to the conditions suitable for the lift off (lift off). In this case, the transfer layer 620 is formed by adjusting the composition of Si, C, Ge, Sn is 0-1, the concentration of impurities is 10 ¹⁹ ~ 5 × 10 ²¹ cm ^-3 .

More specifically, the transfer layer 620 is thermally decomposed on the substrate 610 by using RPCVD, using DCS gas, SiH ₄ gas, or GeH ₄ gas as the main source gas, and H ₂ gas as the balance gas. It grows through the deposition method. At this time, the GeH ₄ gas flow rate is adjusted to change the mixing ratio of Ge to 0 to 100% by varying Si _{1 - X} Ge _X Grow the layer.

And, by adjusting the growth temperature and the flow pressure of the variable Si _{1 - X} Ge _X The thickness of the layer is formed in a predetermined nm to a predetermined µm.

The transfer layer 620 is suitable as an interlayer in GaN epitaxial growth by changing the lattice constant and TEC according to the content of Ge. The SiGe epitaxial layer has a low melting temperature and smooth movement of Ge atoms. When stress is applied, relaxation occurs more easily than Si or GaN-based epilayers. In addition, due to the impurities implanted at a high concentration, the atomic defects are high, and the energy of atomic bonding is low, thereby quickly relieving the stress transferred from the Si and GiN epitaxial layers. Similarly, by using the interlayer of the SiGe-based epilayer, the stress between the Si and GaN-based epilayers is alleviated, thereby reducing the warpage of the wafer and minimizing the occurrence of defects on the GaN side.

As illustrated in FIG. 7C, a buffer layer 630 is formed on the formed transfer layer 620. Here, the buffer layer 630 should be grown at a lower temperature than the transfer layer 620.

Subsequently, as illustrated in FIG. 7D, the transfer layer 620 melts when the temperature is increased for growth of the epi layer after the growth of the buffer layer 630. melting) process.

As shown in FIG. 7E, the nitride layer epi layer 630 grows while the transfer layer 620 is melted. Here, the nitride epitaxial layer 640 is a three-phase, quaternary compound layer of a binary system of GaN, InN, AlN, and a mixture thereof after the buffer layer 630 is grown. The layer is formed into a sandwich-like composite layer.

More specifically, methods of growing the nitride based epilayer 640 include VPE (Vapor Phase Epitaxial growth), LPE (Liquid Phase Epita xial growth), and SPE (Solid Phase Epitaxial growth). have. Here, the VPE is to grow crystals on the substrate through decomposition and reaction by heat while flowing the reaction gas on the substrate, depending on the raw material of the reaction gas, hydride VPE (HVPE), halide VPE (halide VPE), organic Metal organic VPE (MOVPE). The present invention uses the HVPE (hydride VPE) method.

In the case of the substrate 610 in which the nitride based epitaxial layer 640 is grown, the GaCl x gas and the NH 3 gas are flowed into the reactor after the charge into the HVPE reactor, and the temperature of the silicon substrate is maintained at 400 to 600 ° C. . Then, GaCl x gas and NH 3 gas react with each other to form a GaN seed layer, and then a GaN nanorod is formed on the substrate by itself.

Accordingly, the grown nitride epitaxial layer 640 may have a defect due to lattice mismatch between the semiconductor substrate 610 and the nitride epitaxial layer 640 by the floated transfer layer 620. In the case of an epi layer which is relaxed and finally grown in all floating layers, a high-quality epi layer without defects is grown regardless of a lattice constant difference with a semiconductor substrate.

As shown in FIG. 7F, the growth of the group III nitride epitaxial layer 640 is completed on the buffer layer 630 through the above process.

As described above, by using the transfer layer of the present invention, a high quality group III nitride semiconductor epitaxial layer can be grown and a high performance device using the same can be manufactured. In addition, the process steps for manufacturing the device according to the present invention is very simple and accurate, and the mass production and reliability of the product is excellent.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of course, this is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the equivalents as well as the claims that follow.

<Explanation of symbols for detailed description of the drawings>
210, 610 --- Substrate 220, 620 --- Transfer Layer
230, 240 --- Buffer Layer 240, 640 --- Nitride Epilayer

Claims (15)

Claims [1]
A transfer layer formed on the substrate;
A buffer layer formed on the transfer layer;
A nitride based epitaxial layer formed of a group III nitride based material on the buffer layer,
And a melting point of the transfer layer is lower than that of the nitride-based epi layer.
The method according to claim 1,
The transfer layer is a semiconductor substrate on which the III-nitride epitaxial layer is grown, comprising Si _x Ge _{1 - x} .
The method according to claim 1,
The transfer layer may vary the growth of the epi layer by varying the Si _x Ge _1-x composition ratio according to the type of the substrate or the nitride based epi layer. A semiconductor substrate on which a III-nitride epitaxial layer is grown.
The method according to claim 1,
The transfer layer may be formed as a composite layer of a sandwich structure in a single or a plurality of layers depending on the material and composition A semiconductor substrate on which a III-nitride epitaxial layer is grown.
The method according to claim 1,
The substrate is a semiconductor substrate with a grown III-nitride epi layer, characterized in that using a silicon substrate or a sapphire substrate.
Forming a transfer layer on the substrate;
Forming a buffer layer on the transfer layer;
Growing a III-nitride epitaxial layer on the buffer layer;
And the transfer layer is melted when the III-nitride based epitaxial layer is grown.
The method according to claim 6,
The transfer layer is formed of Si _x Ge _{1 - x} III-nitride epitaxial growth method of a semiconductor substrate.
The method according to claim 6,
The transfer layer is a III-nitride epitaxial growth method of a semiconductor substrate, characterized in that the growth of the epi layer is changed by changing the Si _x Ge _1-x composition ratio according to the type of the substrate or the nitride based epi layer.
The method according to claim 6,
The transfer layer is a III-nitride epitaxial growth method of a semiconductor substrate, characterized in that formed as a sandwich layer composite layer in a single or a plurality of layers depending on the material and composition.
The method according to claim 6,
And the transfer layer is formed of a semiconductor material having a lower melting point than the buffer layer and the epi layer.
The method according to claim 6,
The substrate is a III-nitride epitaxial growth method of a semiconductor substrate, characterized in that using a silicon substrate or a sapphire substrate.
The method according to claim 6,
The III-nitride epitaxial layer is GaN, InN, AlN, and a three-phase, quaternary compound layer thereof, wherein a single layer or a plurality of epitaxial layers are formed in a sandwich-like composite layer III. Nitride epilayer growth method.
The method according to claim 6,
Growing the III-nitride based epitaxial layer, and then lifting off the buffer layer and the III-nitride based epitaxial layer from the transfer layer. .
14. The method of claim 13,
The lift-off may include applying a high temperature in the chamber after completion of growth of the III-nitride epitaxial layer to melt the transfer layer to lift off the buffer layer and the III-nitride epitaxial layer. III-nitride epilayer growth method of substrate.
14. The method of claim 13,
The lift-off may include etching the transfer layer after completion of growth of the III-nitride epitaxial layer to lift off the buffer layer and the III-nitride epitaxial layer. Flowering epilayer growth method.

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